Roller grinding mill



l .Sept. 9, 193m.

O. Moo@ Roman calname umn Filed Nov@ zo.4 *1925? 3 Sheets-snelst l Sept. 9,1930. o. Moos ROLLER @BINDING `MILL Filed Nov. so. l192e: s sheets-sheet 2 Sept.- 9, 1930. o. Moos ROLLER GRINDING MILL Filed Nov. 30, 1928 sheets-sheet s Inverti/'077 O15-t0 JTOKO,

' .A the .I Patented Sept.V Q i ,l UNITED STATES PATENTol-Fica`l QTTO HOOG, O3' BRUNSWICK, GEBIANY ROLLER GRINDING HILL p Application med November 30, 1928, Serial No. 322,883, 4and. in Germany December 19, 1987.

My invention relates to improvements in roller grinding'mills, and more particularly to the' mechanism for regulating the feed of grain or other substance to the rollersthere- "5 ofi In order to 'obtain high efficiency in roller grinding mills it is necessary to maintain the grain or other substance to be round 1 in the container' provided above the ceding mechanism of the mill as far as possible at the lsame level. The object of the improvements is to provide an apparatus which is simple in construction and eiective in operation, and with this object in view my invention consists in roviding a loating mem ber within the saidP container, which exactly follows any change of the level of the materiall within the container. Another object of the improvements is to provide a relay or servo-motor in connection with the said floating member for controlling the supply 'of grain from the container to the rollers'.

Withthese and other objects in view my invention consists inthe matters to be described hereinafter and particularly pointed out. in the appended claims, reference being had to the accompanying drawings, in which the same letters of reference have been used to indicate corresponding parts.

In said drawings,

showmg a two roller mill,

Fig. 2, is a top plan yview of Fig. 1,

Fig. 3, is-a' sectional elevation on anfen# larged scale showing the relay controlling the supply of grain, and v Fig. 4, is a sectional elevationl taken on hne 4--4 of Fig.x 3'. In the example s own in the drawings the mill comprises a casing 2 provided at its 40 top with a container u, the said container communicatin chutes 3. Wit in the casing 2 t ere are two ypairs of grinding rollers a, a, one of the airs of rollers only being shown in Fig. 1. A ove the rollers a there are two feed rollers b, cooperating with a feed plate d rockingly mounted on a shaft c and adapted to be set relatively to one of the rollers b into osition for allowing a regulated amount o the material to be lground to pass `from the chute Fig. 1, is an elevation partly in section.

with the yc'asin -2 through 3 tothe rollers a, a, the said amount depending on the sizeof the ap provided between the plate d and the ro er b. Y

The shaft 'c extends to the outside of the casing of the mill, and at its outer end it carries a crank c1 connected by a linke with a lever f rockingly mounted at g, the said lever being jointed to a relay or servo-motor. Preferably the link .e carries a weighted body t tending to draw the link downwardly and to rock the plate d towardsthe roller t for reducing the area of the ap provided between the said plate and ro er.

' The said servo-motor is constructed as follows Beside the top part ofthe casing a container r is mounted, which is illustrated in detail in Figs. 3 and 4. Within the container r lthere is a cylinder fv having a piston h reciprocating therein. The piston rodla,1 of the piston is connected withthe bifurcated outer end of the lever f. 'Thus the position of the plate d depends on the position of the piston k within the cylinder 1) the area of the gap Aprovided by the plate d being increased when the piston is moved downwards. Within the container r there is a certain amount of oil, and the said oil isadapted to be forced into the top part .e of the cylinder 'v by means of a pump y1 carried by the bottom wall of the cylinder and having its suction Y ipe y near the bottom of-the container r.

n the example shown in Figs. 3 and 4 the said pum consists of a pair of gear wheels y rotate at uniform speed by means of a pulley y. The pressure duct y* is connected with the to Within t part .e of the cylinder v. e piston rod h* a valve stem w is guided which controls .an orice a: com municatin with the top part e of the cylinder 'v an with the container r. Thus, when the #valve stem fw closes the said orifice the' oil supplied to the chamber e can not escape, and it drivesthe piston h downwardly, thus liftin the plate d. The stem w is'acted ulpon by a ell crank lever o connected with a ink n, a splring oz carried by the stem tending to pus The sai relay the bell crank lever o into engagement with screw nuts o1.

r is controlled by a floatingl the said container, the said member moving upwardly when there is no grain within the container, and moving downwardly when the material Hows freely through the container. In the example shownin Fig. 1 the said member consists of a spindle z rovided with bars 1 preferably laterally isplaced relativel to each other or arran ed around the said ar on a helix. The said ars i* may be circular in cross-section, or, as shown in thefigurethey are roof-shaped. Thus, when the grain flows downwardly through the container u the member z', 1 is immersed in the grain to a certain depth, and the movement of the bars disposed within the ain is determined by the height of the materlal passing through the container u. Preferably the bars l are shorter at the bottom art of the member than at the top thereo so that the downward movement is greater, the fuller the container u. The member z', 1 controls the said relay, and therefore the position of the late d, the late d leaving a large gap when t ere is muc material within the container u and reducing the area of the said ygap if the amount of material within the container u' is small.

Instead of the member consisting of the bars 1, a disk element having a flat base may be used which floats on or in the material and 'dro s on removal of the material.

rock shaft l, and a crank arm m' secured to the shaft Z is connected with'the link n. If'

the amount of grain within the container u is reduced, the re lating member z', l rises within the container and by. the weight t the mechanismconnected with the regulating member is moved, the link n being pulled forwardly in Fig. 2 and lifting the stem fw away from the orifice Thereforethe oil forced into the chamber z of the cylinder is free to esca e through the said orifice :v and into the ottom part of the container r, so that the piston h is relieved ofthe pressure of the oil, and it is moved upwardly by the weighted body t, thus rocking the plate d downwardly and reducing the area of the gap. On the other hand, if there is much grain within the container u, the member z', 1 moves downwardly with the said grain, the link is pushed rearwardly in Fig. 2, and the stem lw is placed on its seat, so that the piston k is forced downwardly by the pressure of the oil within the chamber '2.

In order to be able to regulate the velocity with which the piston h sinks, it is advisable to provide an outlet orifice 'v1 (Fig. 4) in j the cylinder rv which is lled with liquid below the piston, variable by means of a screw c2, so that it can be made narrower with the result that escape of the oil from the chamber fv is rendered more diilicult.

In order to rovide definite stable regulation of the fee plate d and to avoid oscillations, the spring k which supports the yielding element or lloat in the container u, is so dimensioned that every position of the oat corresponds to a definite position of the servomotor and feed. plate d.

The arrangement described also provides that when the operation of the roller. mill is interrupted for anyA reason the feed plate l closes under the action of a weight or spring owing to the default ofthe oil pressure and to the flowing out of the oil from the chamber z by reason of leakage due to imperfect fit of the parts, or by way of leak passages provided for that purpose.

The point at which the crank o engages the valve stem w (Fig. 3) is adjustable by means of thenuts o1 and the transmission of the movement is rendered resilient by means of the spring o2. l

In order to be able. to limit the opening movement of the feed plate ci the valve stem is threaded and its upper end which carries an adjustable nut 03 is extended above a bridge o4 or other fixed stop. The movement of the stem and accordingly of the servomotor and the feed plate d can be limited by adjusting the nut o", the spring 02 being compressed on further sinking of the float If adjustment of the feed plate opening is not desir'ed i. e. if the plate is to be secured inany position, this can be effected by clamping t e crank o (Fig. 3) to a iixed element o" by means of a clamping screw o7 mounted in a slot o5 in a sector oe connected with the crank 0.

Any other liquid or com ressed air can of course be used' as the drivl g power for the pump i/l instead of oil. Any other source of power, for example, electricity or even a purely mechanical servo-motor can be used instead of the hydraulic or pneumatic operation for the servo-motor. The modifications in the device rendered necessary will be obvious to the expert.

By means of my improved apparatus the level of the grain 4or other substance to be ground within the container u is maintained practically uniform.

While 1n describing the invention reference has been made to a articular example embodying the same I wish it to be understood that my invention is not limited to the construction shown in the drawings, and that various changes may be made in the general arrangement of the apparatus and the construction of its parts without departing from the invention.

I claim: Y

1. In a roller grinding mill having grinding rollers, the combination of a container, means `for regulating -the supply of the material to be vground from said container, power operated means controlling said regulating means, and means controlled by the material within said container for controlling saidpower operated means. s. I 2. 'In a roller grinding mill havinggrind- ,ing rollers, the combination of a container,

4a gate orvalve for regulating the supplyA 'of material from said container, power operated means operatively connected with said gate or valve, and a vyielding device within said container and actuated according to the nism operated by pressure Viiuid connected vce with said regulating means, a pump for supplying pressure fluid to said mechanism,A

means controlling-the iow of the fluid from said pump to said mechanism, `andmeans con.- trolled b v t-he material within said container for operating said controllin means.

4. In a roller grinding mi having grind- ,ing rollers, the combination of a container,

means vfor regulating the supply of the material to be ground from said container, and automatic means tending to set said controlling means into position forl interrupting the supply of material from said container to said rollers, power operated means 'controlling said regulating means, and means controlledby the material within said container for controlling said power operated means.

. 5. In a roller 'grinding mill having grinding rollers, the combination of a container,

' meansA for regulating the supply of the material to be ground `from said container, a cylinder and piston connected with said controlling means, a' ump for continuously supplying pressure uid to said cylinder at one side of the piston, the cylinder being provided at the opposlte side of the piston with' an outlet, means' for varying the area of said outlet, a valve permitting the escapev of the pressure fluid from said cylinder, and means depending on the level of thematerial within said container for controlling said valve.

6. 'In a roller grinding mill having grinding rollers, vthe combination of a container, means for regulating the supply of the* material to be inder, a piston reciprocating therein an a piston rod connected with said regulatin means, means 'for limiting the movement' o said piston and rod, a pump for supplying pressureiuid to said cylinder atl one side of the iston, and means `controlled by the materia within said container for controlling the pressure of the fluid within lsaid c linder.

7. In a grinding mill having grin ing devices, the combinationA of a container, means forregulating the supply of the material to o und from said container, a `lbe ground from said container, a member floating within the material contained in said container and controlling said regulating means.

8.. In a grinding mill having grinding means, the combination of a container, means for regulating the supply of the material to ibe ground from saidcontainer, an elastically supported member Heating within the material contained in said container and controlling said regulating means.

9. In a roller grinding mill having grindp ing rollers, the combination of a container, means for regulating the supply of the material to be ground from said container, a

member comprising laterally projecting rods suspended within said container in position for iioating within the material contained therein and operatively connected with said regulating means.

10. In a roller grindingmill having grinding rollers, the combination of a container,

means for regualting the supply of the material to be ground from said container, a member comprising laterally projecting rods suspended within said container in position for floatin within the` material contained therein an operatively connected with said re `lating means, the arms of said member bein laterally displaced with relation to one anot er. f

'11. In a roller grinding mill having grinding rollers, the combination ofa container,

means forregulating the supply of the material to be ground from said container, a

- f member comprising laterally projecting rods vsuspended within said' container in position for floating within the material contained therein and operatively connected with said 'regulating means, said arms being mounted on said member along a helix.

12. In a roller grinding mill having grinding rollers, the combination of a container, means for regulating the supply of the material to be 4ground from said container, a

member comprising laterally projecting rods suspended within said container in position for iioatin within the material contained therein an' operatively connected with` said regulating'means, said arms bein reduced in length from the top part to the ottom part,

of the member.

13.' In a roller mill having grindingrollers, the combination of a. conj l tainer, means for' regulatingthesupply of the material-to be groundfrom said con-j tainer, a member comprising laterally prolecting rods suspended within said container 1n posltion for floating within the material contained thereingand operatively connected signature.

,OTTO MOOG. g 

